红色荧光粉Na_zCa_(1-x-2y-z)Bi_yMoO_4∶Eu_(x+y)~(3+)发光研究

采用高温固相法制备系列红色荧光粉NazCa1-x-2y-zBiyMoO4∶Eux3++y(y,z=0,x=0.24,0.26,0.30,0.34,0.38;x=0.30,y=0.01,0.02,0.03,0.04,0.05,0.06,0.07,z=0;x=0.30,y=0.04,z=0.38)。用X射线粉末衍射(XRD)法测试了所制样品晶相结构。采用荧光光谱仪对样品的发光性能进行了表征,结果表明:当Eu3+单掺杂量浓度x=0.30时,荧光粉(Ca0.70MoO4∶Eu03.+30)的发光强度最强;当Eu3+-Bi3+共掺杂量浓度y=0.03时,电荷迁移带(CTB)强度达到最强,而对于Eu3+特征发射峰,当共掺杂浓度y<0.03时,位于393 nm处的激发峰强度比464 nm强,共掺浓度y>0.03时,464 nm峰比393 nm峰强,共掺浓度为y=0.04时,393和464 nm处两峰位置强度都达到最强。作为电荷补尝剂的Na2CO3掺入上述荧光粉中后,荧光粉激发和发射强度明显地增强。结果表明,通过调节Bi3+/Eu3+掺杂比例可以改变位于近紫外光393 nm和蓝光区464 nm处激发光相对强度。

Luminescence investigation of Na(z)Ca(1-x-2y-z)Bi(y)MoO4 : Eu(x+y)3+, red phosphors

A series of red phosphors with the composition Na(z)Ca(1-x-2y-z), Bi(y) MoO4 : Eu(x+y)3+ (y, z = 0, x = 0.24, 0.26, 0.30, 0.34, 0.38; x = 0.30, y = 0.01, 0.02, 0.03, 0.03, 0.05, 0.06, 0.07; x = 0.30, y = 0.04, z = 0.38) were prepared via traditional solid-state method. The crystal structures of the obtained phosphors were identified by X-ray powder diffraction (XRD) method. The photoluminescence properties of the samples were characterized by fluorescence spectrophotometer. The results indicated that the concentration of Eu3+ single doped Ca(1-x) MoO4 : Eu3+ with the maximum luminescence intensity was found to be 0.30 (namely, Ca0.70 MoO4 : Eu(0.30)3+); the photoluminescence properties with different ratio of Bi3+/Eu3+ codoped Ca0.70-2y Bi(y) MoO4 : Eu(0.30+y)3+, were also investigated, and the results showed that the charge band (CTB) reached the maximum value when the y value was equal to 0.03; for the characteristic excitation peaks of Eu3+, however, the intensity of the excitation spectral line locating at 393 nm was stronger than that at 464 nm when y < 0.03, while the intensity at 464 nm was greater than that at 393 nm when y > or = 0.03; the intensity of excitation peaks locating at 393 and 464 nm respectively both reached the maximum intensity when the y value was 0.04. The relative intensity of the excitation and emission of the above phosphor was enhanced greatly when Na2CO3 acting as charge compensation was added. The above results showed that the relative intensity between 393 and 464 nm could be changed by adjusting the ratio of Bi3+ /Eu3+ codoping concentrations.